code: def _broadcast_timestamps(csc, dst_timestamps):
      """Broadcast the timestamp of each destination node to its corresponding
      source nodes."""
      count = torch.diff(csc.indptr)
      src_timestamps = torch.repeat_interleave(dst_timestamps, count)
      return src_timestamps
  
file_path: dgl/python/dgl/graphbolt/internal/sample_utils.py
imports: import copy
  from collections import defaultdict
  from typing import Dict, List, Optional, Tuple, Union
  import torch
  from ..base import CSCFormatBase, etype_str_to_tuple
label_desc: Use image node_id 4 for calling a global function with example usage: _broadcast_timestamps(csc, dst_timestamps) and returns: src_timestamps